Palladium Nanoclusters Supported on Propylurea-Modified Siliceous Mesocellular Foam for Coupling and Hydrogenation Reactions
作者:Nandanan Erathodiyil、Samuel Ooi、Abdul M. Seayad、Yu Han、Su Seong Lee、Jackie Y. Ying
DOI:10.1002/chem.200701361
日期:2008.3.27
applications of palladium (Pd) nanoparticles supported on siliceous mesocellular foam (MCF). Pd nanoparticles of 2-3 nm and 4-6 nm were used in reactionsinvolving molecular hydrogen (such as hydrogenation of double bonds and reductive amination), transfer hydrogenation of ketones and epoxides, and coupling reactions (such as Heck and Suzukireactions). They successfully catalyzed all these reactions with excellent
Aminophosphine Phosphinites Derived from Chiral 1,2-Diphenyl-2-aminoethanols: Synthesis and Application in Rhodium-Catalyzed Asymmetric Hydrogenation of Dehydroamino Acid Derivatives
A series of chiral aminophosphine phosphinites DPAMPPs was synthesized from optically active 1,2-diphenyl-2-aminoethanols. The erythro-DPAMPPs were found to serve as excellent ligands for rhodium-catalyzed asymmetric hydrogenation of dehydroaminoacid derivatives. For an array of dehydroaminoacid precursors, remarkably high enantioselectivity (up to 98.4% e.e.) and reactivity (the ratio of substrate/catalyst
Asymmetric Enamide Hydrogenation Using Phosphinite Thioglycosides: Synthesis of <scp>d</scp>- and <scp>l</scp>-Aminoesters Using <scp>d</scp>-Sugars as Catalyst Precursors
Diastereomerically pure cationic Rh(I) complexes derived from phosphinite thioglycosides I were used as catalysts in highly enantioselective hydrogenations of enamides. The conformational similarity of alpha-D-arabinopyranose with beta-L-galactopyranose allows the synthesis of both enantiomers of alpha-amino acid derivatives such as D- and L-DOPA in excellent ee (97% and 98%), using derivatives of the former sugar as catalyst precursors.